How Does Hepatitis Affect the Human Body?
Hepatitis is a medical condition defined by the inflammation of the liver and characterized by the presence of inflammatory cells in the tissue of the organ. The condition can be self-limiting (healing on its own) or can progress to fibrosis (scarring) and cirrhosis.
Hepatitis may occur with limited or no symptoms, but often leads to jaundice, poor appetite and malaise.
Hepatitis is acute when it lasts less than six months and chronic when it persists longer.
Worldwide, hepatitis viruses are the most common cause of the condition, but hepatitis can be caused by other infections, toxic substances (notably alcohol, certain medications, some industrial organic solvents and plants), and autoimmune diseases. It is one of the digestive disorders.
Initial features are of nonspecific flu-like symptoms, common to almost all acute viral infections and may include malaise, muscle and joint aches, fever, nausea or vomiting, diarrhea, and headache.
More specific symptoms, which can be present in acute hepatitis from any cause, are: profound loss of appetite, aversion to smoking among smokers, dark urine, yellowing of the eyes and skin and abdominal discomfort.
Physical findings are usually minimal, apart from jaundice, tender enlargement of the liver, enlarged lymph nodes in 5%, and enlargement of the spleen.
Acute viral hepatitis is more likely to be asymptomatic in children. Symptomatic individuals may present after a convalescent stage of 7 to 10 days, with the total illness lasting weeks.
A small proportion of people with acute hepatitis progress to acute liver failure, in which the liver is unable to remove harmful substances from the blood (leading to confusion and coma due to hepatic encephalopathy) and produce blood proteins (leading to peripheral edema and bleeding).
Chronic hepatitis may cause nonspecific symptoms such as malaise, tiredness and weakness, and often leads to no symptoms at all.
It is commonly identified on blood tests performed either for screening or to evaluate nonspecific symptoms.
The presence of jaundice indicates advanced liver damage. On physical examination there may be enlargement of the liver.
Viral hepatitis is the most common cause of hepatitis worldwide. The most common causes of viral hepatitis are the five unrelated hepatotropic viruses hepatitis A, hepatitis B, hepatitis C, hepatitis D (which requires hepatitis B to cause disease), and hepatitis E.
Other common causes of non-viral hepatitis include toxic and drug-induced, alcoholic, autoimmune, fatty liver, and metabolic disorders. Less commonly some bacterial, parasitic, fungal, mycobacterial and protozoal infections can cause hepatitis.
Additionally, certain complications of pregnancy and decreased blood flow to the liver can induce hepatitis. Cholestasis (obstruction of bile flow) due to hepatocellular dysfunction, biliary tract obstruction, or biliary atresia can result in liver damage and hepatitis.
Diagnosis is made by assessing an individual's symptoms, physical exam, and medical history, in conjunction with blood tests, liver biopsy, and imaging. Blood testing includes blood chemistry, liver enzymes, serology and nucleic acid testing.
Abnormalities in blood chemistry and enzyme results may be indicative of certain etiologies or stages of hepatitis. Imaging can identify steatosis of the liver but liver biopsy is required to demonstrate fibrosis and cirrhosis.
A biopsy is unnecessary if the clinical, laboratory, and radiologic data suggests cirrhosis.
Furthermore, there is a small but significant risk to liver biopsy, and cirrhosis itself predisposes for complications caused by liver biopsy.